I have been using energizers for years, the first energizers were real good after charging they lasted a long time ( 4 sets of 2500 nmh ) . The new and improved energizers do last a long time after charging at least four months. I use the new sets ( 4 sets of 2300 nmh ) mostly in my RC cars and monster trucks, the servos suck power from these battires but they keep puting out power for hour-long performance, in the transmitter they last for weeks and Won't discharge, Also I use the same batteries in my cameras and they really last, shooting alot of photos. Another great use is in x box controler, last a long long time. Buying energizers batteries saves a lot of money and running RC vehicles regular batteries dont last long. Use the charger, I have two and they work perfect.